• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.203-207
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• 2014

According to the advanced study, Increase of ceiling air space could cause increase of floor impact sound by air-spring effect. So in this research, we studied the increase of floor impact sound caused by ceiling air space in apartment buildings. At first, we evaluated the change of floor impact noise in the condition of with or without ceiling air-space. And then we installed perforated ceiling systems and glass wool at ceiling area. we expected that perforated ceiling systems could prevent air-spring effect in ceiling space. As a result, ceiling air space caused increasement of floor heavy impact noise about 2~4dB. But perforated ceiling & sound-absorbing materials system could give us reduction of heavy floor impact noise about 3dB. So this systems could be a good alternative to obey national regulations, because it can reduce heavy impact noise additional to floating floor systems.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.211-212
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• 2012

To prevent energy waste in buildings used heat insulator. Heat insulator materials can be classified inorganic and organic. The organic material is due to toxic gas emission, when a fire occurs. And it has lower water resistance. The inorganic material is heavy and worse thermal performance than organic materials. Technologies on energy saving and materials used in curtain walls have progressed with increase of high-rise and large buildings. However, there is little study to explain fire resistance performance of the curtain walls. This study focused on evaluation of the physical properties of light-weight inorganic foam panel for using industrial by-products materials and performance evaluation by mock up test.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.79-81
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• 2011

To prevent energy waste in buildings used heat insulator. Heat insulator materials can be classified inorganic and organic. The organic material is due to toxic gas emission, when a fire occurs. And it has lower water resistance. The inorganic material is heavy and worse thermal performance than organic materials. This study focused on evaluation of the physical properties and fire-resistance of inorganic foam material for using industrial by-products materials for the applicability of Fire-resistance Light-weight material.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.119-120
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• 2016

This study is about development of inorganic insulation material using by-product materials. The organic material is due to toxic gas emission, when a fire occurs. And it has lower water resistance. The inorganic material is heavy and worse thermal performance than organic materials. In this study, installed light weight ceramic insulation by concrete structure to evaluation fire resistance.

• Special Issue of the Society of Naval Architects of Korea
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• 2009.09a
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• pp.80-86
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• 2009

In order to improve productivity of large container ship construction, large heat input and/or high productive welding technologies are necessary. This can be achieved by the joint research and cooperation among steel maker, welding consumable company, welding equipment company and ship yards. Two electrodes SAW process is effective the plate butt welding and partial joint welding, while FGB welding process is for the connection of block to block joint. The higher strength and thicker steel is developed, the more reliable welding procedure such as two electrodes EGW including light weight welding equipment should be developed.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.170-173
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• 2004

The law about floor impact sound goes into effect from March 23th in 2004 and is applying to new designs. According to the new law, the minimal of slab thickness is 180mm by standard floor structure and the new law presents about the minimal standard about heavy-weight impact sound. Also, It presents about classification of light-weight sound separate the minimal standard, so demand of consumers can be accepted. But a working plan of classification about light-weight sound is not presented in accordance with field test, so the problem that design can't be achieved although the aim of design is formed. This study shows contents to investigate for working of classification and will be helpful to designers and construction corporations.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.10-11
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• 2020

Currently, the most used forms, such as euro form and aluminum form, has many problems. There are issues with noise of construction site because of existing forms' material and issues with safety because of heavy weight. To solve these problems, there are many researches on using plastic and composite materials on the formwork. However, plastic has lower tensile strength than the steel and aluminum and composite materials are expensive. Therefore, constructors are avoid to use the forms with new materials. The purpose of this study is to develop light-weight plastic form to solve these existing problems by using ABS with optimized design. To verify, the study measured the amount of deflection from developed form through a load test. The test result showed a deflection of 1.15mm when 1.4ton was loaded in the middle of form. The result of the study verified that the usage of ABS and optimized design effectively reduced the weight and noise. Also, it's performance was verified through the load test.

• International Journal of Highway Engineering
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• v.16 no.4
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• pp.11-19
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• 2014

PURPOSES: This study is to suggest the improvement for bus rapid transit system in Seoul METHODS: The maintenance cost for bus lane damages and plastic deformations are increased by bus passing speed, heavy bus weight, and climate change (localized torrential downpour, subtropical climate) and the accident risk has been increased. RESULTS: Recent analysis of pavement damage indicates that bus lane damage caused by heavy weight is overwhelming and it is urgent to prepare countermeasures. CONCLUSIONS : Pavement data of bus rapid transit system, bus transit numbers and pavement damage elements were analyzed. By analyzing pavement maintenance, design and construction, the countermeasures for the improvement of bus lane pavement and effective maintenance were suggested.

• Journal of Korea Foundry Society
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• v.10 no.6
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• pp.520-527
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• 1990

In order to reduce segregation in 12%Cr steel ingots of 60-100tons, numerical analysis by computer was applied to simulate solidification profiles and the profiles of liguid-solid coexisting zone in accordance with the ratios of H(Height) /D(diameter) of 100-ton ingot. The result is that the ratio of L(vertical length) /D(diameter) of liquid-solid coexisting zone was reduced in proportion to the decrease of H/D ratio. With the reduced H/D ratio(0.92) of ingot, the segregation in 60-ton ingot of 12% Cr steel can be much reduced and recovery was also improved by reducing ingot weight.

• Land and Housing Review
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• v.5 no.2
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• pp.81-89
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• 2014

This paper presents various attempts to secure the floor impact sound insulation performance on the dry floor system of steel framed modular house that lately attracted domestic attention. Test results show that in the condition of using dry floor system of D31(D32), the light-weight impact noise performance records the top level in the floor impact sound insulation performance grading system. the heavy-weight floor impact noise performance meets the minimum sound level limit in the floor impact sound insulation performance grading system that enacted regulation on housing construction standards.